Messages in this thread Patch in this message | | | From | Tejun Heo <> | Subject | [PATCH 14/17] scsi: replace custom rq mapping with blk_rq_map_kern_sgl() | Date | Wed, 1 Apr 2009 22:44:29 +0900 |
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Impact: hack removal
SCSI needs to map sgl into rq for kernel PC requests; however, block API didn't have such feature so it used its own rq mapping function which hooked into block/bio internals and is generally considered an ugly hack. The private function may also produce requests which are bigger than queue per-rq limits.
Block blk_rq_map_kern_sgl(). Kill the private implementation and use it.
Signed-off-by: Tejun Heo <tj@kernel.org> --- drivers/scsi/scsi_lib.c | 108 +---------------------------------------------- 1 files changed, 1 insertions(+), 107 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 3196c83..3fa5589 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -296,112 +296,6 @@ static void scsi_end_async(struct request *req, int uptodate) __blk_put_request(req->q, req); } -static int scsi_merge_bio(struct request *rq, struct bio *bio) -{ - struct request_queue *q = rq->q; - - bio->bi_flags &= ~(1 << BIO_SEG_VALID); - if (rq_data_dir(rq) == WRITE) - bio->bi_rw |= (1 << BIO_RW); - blk_queue_bounce(q, &bio); - - return blk_rq_append_bio(q, rq, bio); -} - -static void scsi_bi_endio(struct bio *bio, int error) -{ - bio_put(bio); -} - -/** - * scsi_req_map_sg - map a scatterlist into a request - * @rq: request to fill - * @sgl: scatterlist - * @nsegs: number of elements - * @bufflen: len of buffer - * @gfp: memory allocation flags - * - * scsi_req_map_sg maps a scatterlist into a request so that the - * request can be sent to the block layer. We do not trust the scatterlist - * sent to use, as some ULDs use that struct to only organize the pages. - */ -static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl, - int nsegs, unsigned bufflen, gfp_t gfp) -{ - struct request_queue *q = rq->q; - int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT; - unsigned int data_len = bufflen, len, bytes, off; - struct scatterlist *sg; - struct page *page; - struct bio *bio = NULL; - int i, err, nr_vecs = 0; - - for_each_sg(sgl, sg, nsegs, i) { - page = sg_page(sg); - off = sg->offset; - len = sg->length; - - while (len > 0 && data_len > 0) { - /* - * sg sends a scatterlist that is larger than - * the data_len it wants transferred for certain - * IO sizes - */ - bytes = min_t(unsigned int, len, PAGE_SIZE - off); - bytes = min(bytes, data_len); - - if (!bio) { - nr_vecs = min_t(int, BIO_GUARANTEED_PAGES, - nr_pages); - nr_pages -= nr_vecs; - - bio = bio_alloc(gfp, nr_vecs); - if (!bio) { - err = -ENOMEM; - goto free_bios; - } - bio->bi_end_io = scsi_bi_endio; - } - - if (bio_add_pc_page(q, bio, page, bytes, off) != - bytes) { - bio_put(bio); - err = -EINVAL; - goto free_bios; - } - - if (bio->bi_vcnt >= nr_vecs) { - err = scsi_merge_bio(rq, bio); - if (err) { - bio_endio(bio, 0); - goto free_bios; - } - bio = NULL; - } - - page++; - len -= bytes; - data_len -=bytes; - off = 0; - } - } - - rq->buffer = rq->data = NULL; - rq->data_len = bufflen; - return 0; - -free_bios: - while ((bio = rq->bio) != NULL) { - rq->bio = bio->bi_next; - /* - * call endio instead of bio_put incase it was bounced - */ - bio_endio(bio, 0); - } - - return err; -} - /** * scsi_execute_async - insert request * @sdev: scsi device @@ -438,7 +332,7 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd, req->cmd_flags |= REQ_QUIET; if (use_sg) - err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp); + err = blk_rq_map_kern_sg(req->q, req, buffer, use_sg, gfp); else if (bufflen) err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp); -- 1.6.0.2
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